Dithia-dioxo-hydrocarbons



DITHIA-DIOXO-HYDROCARBONS Ralph B. Thompson, Hinsdale, 11]., assignor toUniversal Oil Products Company, Des Plaines, 111., a corporation ofDelaware N Drawing. Application November 17, 1953, Serial No. 392,737

Claims. (Cl. 260-586) This. application is a continuation-in-part of mycopending application Serial No. 175,018, filed July 20, 1950, nowabandoned, and relates to novel compositions of matter.

The novel compositions of matter comprise certain dithia-diketones inwhich the keto and sulfur groups are in a specific relation to eachother.

In a specific embodiment the present invention relates to a novelcomposition of matter comprising a 4,5-dithia- 1,8 diketone.

In a more specific embodiment the present invention relates to a,novelcomposition of matter comprising 5,6- dithia-2,9-diketodecane.

In still another specific embodiment the present invention relates to anovel composition of matter comprising5,6.-dithia-4,4-,7,7-tetramethyl-2,9-diketodecane.

The novel compositions of matter may be illustrated by. thefollowinggeneral formula:

Re Re H wherein each of R1, R2, R3 and R4 is separately andindependently selected from the members of the groups consisting ofhydrogen, hydrocarbon, substituted hydrocarbon, heterocyclic andsubstituted heterocyclic groups.

The hydrocarbon group preferably is selected from alkyl, alkenyl,cycloalkyl, cycloalkalkyl, alkcycloalkyl, aryl,, alkaryl and aralkyl.vThe substituted groups may contain such radicals as hydroxyl amino,monoalkylamino, di'alkylamino, etc.

In another form of the invention, R1 and R4 may comprise carbon atomsforming a polymethylene ring.

It will be noted from the general formula hereinbefore set; forth thatthe ketogroups are attached to carbon atoms in positions beta to thesulfur atoms and that thesulfur atoms are attached to each other. Thisspecific configuration is present in all of the novel compositions ofthe. present invention and is essential thereto. These compounds. areuseful as antioxidants in retarding oxidative deterioration of organiccompounds, including edible fats and oil, motor fuels and particularlycracked gasoline,

polymer gasoline, etc., diesel oil, mineral oil, lubricating oil,fueloil, drying oil, greases, rubber, etc. These-compounds also may findutility as intermediates in various organic synthesis.

The novel compounds of the present invention may be prepared in anysuitable manner. In a preferred method these, compounds are prepared by;reacting an alpha-betaunsaturated carbonyl compound; namely, analpha-betaunsaturatedketone or an'alpha-beta-unsaturated; aldehyde, withhydrogen sulfideto form a mercapto-carbonyl compound, which then isoxidized to the dithiaediketo: compound;

The carbonyl compounds used as startingmaterialsin the present processinclude both aldehydesiand keIQneS-i which may be representedby theformula:

apt-Mas.

wherein R1, R2, R3 and R4 each separately and independently represents amember of the groups consisting of hydrogen, hydrocarbon, andheterocyclic groups. The hydrocarbon groups which are represented by R1,R2, R3. and R4 include alkyl, alkenyl, cycloalkyl, cycloalkalkyl,alkcycloalkyl, aryl, alkaryl and aralkyl groups. The heterocyclic ringswhich are represented also by R1 to R4 include a thiophene ring, a furanring, a pyridine ring, etc. In general, alpha-beta-unsaturated ketonesare preferred and particularly those in which R4 represents ahydrocarbon group, and each of R1, R2 and R3 represents a hydrogen atom,or R1 and R3 represent hydrogen atoms and R2 represents a hydrocarbongroup, particularly an alkyl group.

The reaction of hydrogen sulfide with an alpha-betaunsaturated ketone iseffected readily by contacting these reacting materials using a largeexcess of hydrogen sulfide generally at a temperature of from about 0 toabout C. and preferably in the presence of a basic catalyst. Ketonescontaining at least one hydrogen atom combined with the carbon atom inbeta position to the keto group react readily with hydrogen sulfide inthe presence of a basic catalyst such as piperidine, sodium methylate,quaternary ammonium hydroxides, and other basic catalysts. In somecases, it is desirable to heat the reaction mixture at a temperature offrom about 50 to about 100 C. in order to promote the reaction. In mostcases it i necessary to use a large excess of hydrogen sulfide to avoidformation of the thiaketones wherein one molecule of hydrogen sulfide iscombined with two molecules of alpha-.beta-unsaturated ketone.

The mercapto-carbonyl compounds and particularly mercapto-ketones, whichare formed by reacting hydrogen sulfide with an alpha-beta-unsaturatedcarbonyl compound, are converted into dithia-l,8-diketones by anoxidation treatment, such as by blowing air or another oxygencontaininggas through the liquid mercapto-carbonyl compound, particularly mercaptoketone, at a temperature of from about 20 to about 100 C.

In this step of the process mild oxidizing agents as peroxides, etc.also may be utilized to bring about the oxidative condensation of twomolecules of the mercaptocarbonyl compound to form one molecule of adithia- 1,8-diketone.

The following preparations are" illustrative of the large number ofcompounds which may be prepared and used within the scope of the presentinvention. It is understood that all of these compounds are notnecessarily of equivalent activity for all uses. These compounds areprepared in accordance with the general procedure hereinbefore setforth.

The following specific compounds comprise those in.

which R1, R2 and R3 are hydrogen and R4 is an alkyl group. 5,6 dithia2,9 diketodecane is prepared by the reaction of methyl vinyl ketone withhydrogen sulfide dithia=diketooctadecane, dithia-diketoeicosane, dithia.diketodocosane, dithia diketotetracosane, etc., may be.

' prepared by utilizing, as starting material, amyl vinyl Patented May28, 1957- 8,9-dithia-5,IZ-diketohexadecane is ketone, hexyl vinylketone, heptyl vinyl ketone, octy alkenyl radical, 7,8 dithia 4,11diketotetradecadiene-- 1,13 may be prepared by the reaction of allylvinyl ketone with hydrogen sulfide and subsequent oxidative condensationof the intermediate product. Similarly, 7,8-dithia- 2,13 dimethyl 4,11diketotctradecadiene 1,13 may be prepared by the reaction of methallylvinyl ketone with hydrogen sulfide, followed by oxidative condensation.Still further, 8,9 dithia 5,12 diketohexadecadiene- 2,14 may be preparedby the reaction of crotyl vinyl ketone with hydrogen sulfide andoxidative condensation of the intermediate product.

As representative of compounds in which R4. is a cycloalkyl radical, 4,5dithia 1,8 'dicyclohexyl 1,8 diketooctane may be prepared by thereaction of cyclohexyl vinyl ketone with hydrogen sulfide, followed byoxidative condensation. alkcycloalkyl radical may be prepared by thereaction of ethylcyclohexyl vinyl ketone with hydrogen sulfide andoxidative condensation of the intermediate product to form 4,5 dithia1,8 diketooctane.

As illustrative of compounds containing aryl groups, 4,5 dithia 1,8diphenyl 1,8-diketooctane may be prepared by the reaction of phenylvinyl ketone with hydrogen sulfide to form phenyl beta-mercaptoethylketone, followed by oxidative condensation thereof. Similarly, ,5-dithia 1,8 dinaphthyl 1,8 diketooctane may be prepared by the reactionof naphthyl vinyl ketone with hydrogen sulfide and oxidativecondensation of the intermediate product. Illustrative compounds inwhich R1 and R4 are phenyl radicals, 4,5 dithia 1,3,6,8 tetrap-he'nyl'1,8 diketooctane may be prepared by the reaction of benzalacetophenonewith hydrogen sulfide and oxidative condensation thereof. Illustrativeof compounds containing both alkyl and phenyl radicals (R1 beingflphenyland R4 being alkyl), 5,6-dithia-4,7-diphenyl- 2,9-diketodecane may beprepared by the reaction of benzalacetone with hydrogen sulfide,followed by oxidative condensation. In4,5-dithia-1,3,6,8-tetraphenyl-3,6- dirnethyl-1,8-diketooctane, R1 isalkyl radical and R2 and R4 are phenyl groups. This compound is preparedby the reaction of dypnone with hydrogen sulfide, followed by oxidativecondensation of the intermediate product. Compounds containing alkarylgroups are illustrated by 4,5 dithia 1,8 ditolyl 1,8 diketooctane, whichmay be prepared by the reaction of tolyl vinyl ketone with hydrogensulfide and oxidative condensation of the intermediate product, and by.4,5-dithia-1,8-dixylyl-1,8- diketooctane which may be prepared by thereaction of xylyl vinyl ketone with hydrogen sulfide, followed byoxidative condensation.

As illustrative of compounds containing. heterocyclic groups, 4,5 dithia3,6 diphenyl 1,8 difuryl 1,8.-

'diketooctane may be prepared by the reaction of benzaldisulfide may beprepared by the reaction of cyclo-' hexenone-2 with: hydrogen sufide andoxidative condensa'tion. v

A compound containing an I di (ethyl cyclohexyl) While the ketonesgenerally are preferred as reactants, it is understood that thealdehydes may be used in preparing the novel compounds of the presentinvention. Thus, 4,5-dithiaoctane-1,8-dial may be prepared by thereaction of acrolein with hydrogen sulfide and oxidative condensation ofthe intermediate product, and 4,5-dithia- 3,6 dimethyloctane 1,8 dialmay be prepared by the reaction of crotonaldehyde with hydrogen sulfideand subsequent oxidative condensation. Similarly, 4,5-dithia-3,6-diphenyloctane-1,8-dial may be prepared by the.reaction ofcinnamaldehyde with hydrogen sulfide and oxidative condensation of theintermediate product. Other compounds may be prepared by starting withdifferent alpha-beta unsaturated aldehydes.

The following examples are introduced to illustrate further the noveltyand utility of the present invention but not with the intention ofunduly limiting the same;

Example I 5,6-dithia-2,9-diketodecane was prepared by reacting methylvinyl ketone with hydrogen sulfide to-form methyl beta-mercaptoethylketone which was then oxidized with hydrogen peroxide to form5,6-dithia-2,9-diketodecane. 4

Example 11 In order to show the inhibitor potency of thedithiadiketodecane, prepared in accordance with Example I,

0.02% by weight of this compound was added to lardwhich had a normalstability period of 5 hours. The lard "'9 until rancidity is determinedorganoleptically and by.

pared by reacting mesityl oxide with hydrogen sulfide] so inhibited hada stability period of 17 hours. The stability period of the lard wasdetermined by the Swift test, which is described in detail in thearticle by A. E. King, H. L. Roschen, and W. H. Irwin, in the Oil and asdescribed in thearticle by R. W. Reimenschneider, J. Turer and R. M.Spec, which appeared in the Oil and Soap, pages 169, 171, September1943. In general, the test comprises bubbling air through a sample ofthe lard peroxide. value, the lard being limited to a peroxide number of20. 1

7 Example III 5,6-dithia-4,4,7,7-tetramethyl-2,9-diketodecane was preandoxidative condensation of the product. Mesityl oxide was reacted withhydrogen sulfide specifically as followsif To mesityl oxide (504 g.) wasadded 1 g. of 40% sodium methylate in methanol, and hydrogen sulfide waspassed into the mixture with rapid stirring. The excess of hydrogensulfide is not necessary here as the two methyl groups on the ,B-carbonatom hinder. formation of the thiadiketone; While the hydrogen sulfidewas being" added, a total of 4.5 gaadditional, sodium methylate wasadded. After the addition of 122 g. of hydrogen sulfide,

the reaction mixture was washed twice with very dilute sulfuric acid andonce with water.

The product was 7 distilled in vacuum to yield 349 g. of2-methyl-2-mercapto-4-pentanone, a yield of 74% based on the hydrogensulfide.

' Analysisg calculated for CsHmOS: 24.2% S. Found:

30% hydrogen peroxide (100 g.) was added with vigorou's stirring to 220g. of the 2-methyl-2-mercapto-4- pentanone,'prepared in the abovemanner, and 100 cc.

of glacial acetic acid. The reaction mixture was cooled sufliciently tohold'the temperature between -95 C. The mixture was diluted with waterand extracted with a hydrocarbon solvent, the solvent subsequently beingremoved by vacuum distillation. A portion of the product was distilledat 0.7 mm., boiling point 137-142" C Fauna-24.4% s.

Analysis. -Calculated for CnHzzOzSz: 24.4%

reacting crotonaldehyde with hydrogen sulfide, separating the resultantmercaptoaldehyde, and oxidatively condensing it with hydrogen peroxide.

I claim as my invention:

1. A dithia-dioxo-hydrocarbon having the following general formula:

wherein each of R1, R2, R3 and R4 is separately and independentlyselected from the group consisting of hydrogen and hydrocarbon radicals.

2. A 4,5-dithia-1,8-diketooctane which is free of nonhydrocarbonsubstituents.

3. A 4,5-dithia1,8-diary1-1,8-diketooctane which is free ofnon-hydrocarbon substituents.

4. 4,5-dithia-1,8-dipheny1-1,8-diketooctane.

5. A 4,5-dithia-1,8-dicyc1oalky1-1,8-diketooctane which is free ofnon-hydrocarbon substituents.

6. 4,5-dithia-1-8-dicyc1ohexyl-1,8-diketooctane.

7. 4,5-dithia-1,8-ditolyl-1,8-diketooctane.

8. A 5,6-dithia-2,9-diketodecane which is free of nonhydrocarbonsubstituents.

9. 5,6-dithia-2,9-diketodecane.

10. 5,6-dithia-4,4,7,7-tetramethyl-2,9-diketodecane.

References Cited in the file of this patent UNITED STATES PATENTS1,908,935 Tschunkur et a1. May 16, 1933 2,010,828 Rothrock Aug. 13, 19352,028,246 Rider et a1. Jan. 21, 1936 2,212,150 Burke Aug. 20, 19402,492,235 Chenicek et a1 Dec. 27, 1949 2,492,336 Thompson et a1. Dec.27, 1949

1. A DITHIA-DIOXO-HYDROCARBON HAVING THE FOLLOWING GENERAL FORMULA: